Articles of manufacturing prepared from polymers of hydrazine or dihydrazides and tricarboxylic acid anhydrides

ABSTRACT

Novel polymers formed from the reaction of tricarboxylic anhydrides and hydrazines or hydrazides which may be cross-linkable by further reaction with a hydrazine or hydrazide are disclosed.

This is a division of application Ser. No. 369,629, filed June 13, 1973,and now U.S. Pat. No. 3,882,086.

DESCRIPTION OF INVENTION

Briefly this invention comprises novel polymers preferably formed fromthe reaction of a tricarboxylic anhydride and a monofunctional alcoholto form an ester-acid of the formula: ##EQU1## which is subsequentlyreacted with a hydrazine or hydrazide to form a polysalt having thestructural formula: ##EQU2## the above polysalt is then heated to form acompound of the structural formula: ##EQU3## the above (III), when R isaldehyde ketone, aliphatic chlorine, bromine or iodine functional, canbe further reacted with a hydrazine or hydrazide to form a cross-linkednetwork. By aliphatic chlorine, bromine or iodine functional is meantany aliphatic radical having a chlorine, bromine or iodine atom or atomsand includes aromatics having aliphatic groups containing chlorine,bromine, or iodine atoms thereon connected to the aromatic ring.

In the above formulae R is a trivalent organic radical having at least 2carbon atoms. Examples of trivalent organic radicals are, but notlimited to the aromatic trivalent radicals of the structure: ##SPC1####SPC2##

And the like, and the aliphatic and cycloaliphatic trivalent organicradicals, such as ##SPC3## ##EQU4## and the like. R₁ is a divalentorganic having at least 2 carbon atoms; examples of said divalentorganic radicals are, but not limited to, the aromatic divalent organicradicals, such as: ##SPC4##

And the like, and the divalent organic aliphatic radicals, such as

     (CH.sub.2).sub.n

wherein n is 2 to 34, ##EQU5## ##SPC5## ##SPC6## ##SPC7##

    --C.tbd.C--,  and the like.

R' is a monovalent alkyl cycloalkyl or alkenyl radical having 1 to 20carbon atoms.

R₂ and R₃ are selected from the group consisting of monovalent alkyl,aryl, aralkyl, cycloalkyl, heterocycloalkyl and hydrogeno radicals andisomers thereof, and x and y are either 0 or 1.

Any hydrazine or dihydrazide is suitable for cross-linking the compoundsof formula III (when R is ketone, aldehyde, aliphatic chlorine, bromineor iodine containing), provided the hydrazine or dihydrazide has twoterminal -- NH₂ groups, examples of hydrazines useful for cross-linkingare, but not limited to; hydrazine, 1,2-ethylene dihydrazine,p-phenylene dihydrazine, alpha, alpha'-diethyl-m-phenylene dihydrazine,and the like; examples of hydrazides are, but not limited to, succinoyldihydrazide, adipoyl dihydrazide, isophthaloyl dihydrazide,terephthaloyl dihydrazide, pyridine-2,4-dicarbonyl dihydrazide and thelike.

The cross-linking reaction is accomplished, when R is aldehyde or ketonefunctional, by reacting the carbonyl containing polymer with thehydrazine or hydrazide to form a cross-linking bridge of the structure##EQU6## wherein R₁, R₂, R₃, x and y are of the structures and values aspreviously described.

The cross-linking reaction is effected by the ketone or aldehydecarbonyl reacting, i.e., condensing, with the terminal -- NH₂ group ofthe hydrazine or hydrazide employed to produce the cross-linked polymerand the water of condensation as a by-product. When the functionality ofR is aliphatic chlorine, bromine or iodine, the terminal -- NH₂ groupsof the hydrazine or hydrazide react with the halogen bearing carbon atomto produce a cross-linking bridge of the structural formula ##EQU7##wherein R₁, R₂, R₃, x and y are of the structures and values aspreviously described.

Hence, the physical properties of the final polymeric material can beadjusted by the degree of cross-linking of the polymer. Further, thedegree of cross-linking can be varied by the amount of ketone, aldehyde,aliphatic chlorine, bromine or iodine functional tricarboxylic anhydrideused in the synthesis of the polymer. The degree of cross-linking canalso be varied by the stoichiometric amount of the hydrazine or thehydrazide used in the synthesis of the polymer. Therefore, a wide rangeof chemical and physical properties of the cross-linked polymer can beachieved, making the cross-linked polymers of the instant inventionadaptable for a plurality of uses.

The polymers of the instant invention can be further modified bysubstituting a portion of the hydrazine or dihydrazide in formula IIwith a diamine, thereby introducing polyimide groups into the polymerchain. Suitable diamines for the aforementioned purpose are, but notlimited to, ethylene diamine, 4,4'diamiodiphenyl propane,4,4'diaminodiphenyl methane, benzidine, 3,3'-dichloro-benzidine;4-4'diaminodiphenyl sulfide; 3,3'diaminodiphenyl sulfone;1,5-diaminonapthalene, meta-phenylenediamine, para-phenylene-diamine;3,3'dimethoxy benzidine and the like.

In addition to the modification of the polymers of the instant inventionby means of substitution of a diamine for the hydrazine or dihydrazide,the polymers can be modified by substituting a portion of thetricarboxylic dianhydride with a tetracarboxylic dianhydride for thepurpose of providing additional ##EQU8## groups along the polymer chain.These tetracarboxylic - hydrazine or hydrazide reaction products beingmore fully described in copending application Ser. No. 369,628, filedconcurrently herewith.

The preferred method of forming the polymers of the instant inventioncomprises: admixing 1 mole of tricarboxylic dianhydride with a suitablesolvent, adding 1 mole of monofunctional alcohol to form the acid -ester of formula I, subsequently adding the hydrazine or dihydrazide (ina sufficient amount to form either the cross-linked or noncross-linkedpolymer on heating) to produce the polysalt of formula II. At this stagethe solution can be further reduced in polysalt concentration by theaddition of an aqueous nitrogenous base solution consisting of aqueousammonia or amine solution or additional organic solvent. The polysalt,either aqueous or non-aqueous, can be coated on a substrate such asglass, glass fibers, metal, wood or the like and heated to a temperatureof about 200°C. to form either the compound of formula II or thecross-linked version thereof.

Another method of forming the polymers of the instant inventioncomprises admixing 1 mole of the tricarboxylic dianhydride with themonofunctional alcohol to form the ester - diacid of the tricarboxylicacid, and subsequently adding the hydrazine or dihydrazide (in an amountsufficient to form either the cross-linked or noncross-linked polymer onheating) and subsequently heating the mixture to above 100°C. to form apolysalt having the structural formula: ##EQU9##

The above method has been characterized by specific molar amounts ofreactants, however different molar amounts may be used providing themolar ratios of the reactants remain the same.

The latter method of forming the polymers of the instant invention isdesired in order that the hydrazine or hydrazide is chemically bonded tothe trifunctional R group, hence, eliminating the possibility ofvaporization of the hydrazine or hydrazide on subsequent heating causinga disproportionation of the stoichiometry of the reactants.

Suitable solvents for admixing with the tricarboxylic anhydride arethose having a high degree of polarity. Examples of such solvents areN-N-dimethyl acetamide; N,N-dimethyl formamide; dimethyl sulfoxide;N-methyl pyrrole, methyl isobutyl ketone, ethyl alcohol and the like.

Transesterification catalysts can be used to aid in the conversion ofthe polysalt to the polymer of formula III. Examples of suchtransesterification catalyst are, but not limited to, oxalic acid,dimethyl terephthalate, dibutyl sebacate, butyl stannoic acid and thelike.

Coating techniques known to those skilled in the art can be used fordepositing the polysalts of formula II on the desired substrate. Forexample, when the compound of formula III is to be used as a binder forglass fibers, application can be achieved by dipping a mat of glassfibers, or glass fiber paper into an aqueous ammonia polysalt (formulaII) solution and allowing the glass fiber material to soak into saidglass fibers (approximately 1 to 30 seconds). After soaking, the glassfiber material is permitted to drip dry and then is subsequently bakedat approximately 250°F. to 300°F. for about 30 to 60 minutes. Thus,fiber glass paper or fiber glass mat is produced which may toleratetemperatures of up to greater than 500°F. without substantial loss ofstrength or integrity.

The polymers of the instant invention can be used as binders for fiberssuch as cotton, hemp, wool, hair, silk, rayon, nylon, Orlon, saran,Ardil; and the like in addition to glass fibers to impart temperatureresistance and strength to the aforementioned fibers.

Fiber reinforced laminates and castings and nonreinforced castings canbe produced by the polymers of the instant invention where certainchemical and physical properties are desired.

Further, coated metallic conductive wire such as copper or zinc, can beproduced by dipping the selected wire into the polysalt (formula II)solution, (the solution being aqueous or nonaqueous) and subsequentlyheating the polysalt coated wire to a temperature adequate to convertthe polysalt to the polymer of formula III or a cross-linked versionthereof. Wire coated by polymers having the repeating structural unit of(formula III) or the cross-linked version thereof may withstand servicetemperatures of 400°F. without any observable degeneration of thepolymer coating; thus, an insulated wire is produced capable ofwithstanding elevated service temperatures. The coating thickness on thesurface of the wire can be adjusted by the viscosity of the polysaltsolution. A low (25 centipoises at 20°C.) viscosity polysalt solutionwould produce a thin coating (≈10 microns) and a high viscosity (≈1000centipoises at 20°C.) polysalt solution would produce a thick coating(about 30 microns).

Also, flat or contoured substrates such as the cellulosics includingwood, paper and the like; glass, metal and the like can be coated withthe polysalt of formula II by spraying the low viscosity polysaltsolution by conventional spraying techniques; by applying the polysaltsolution with a standard paint brush, by depositing the polysaltsolution by any other conventional coating techniques; the techniqueselected being contingent on the substrate and film thickness desired.

The polysalt can be pigmented with pigments such as titanium dioxide,zinc oxide, calcium carbonate, lithopone, phthalocynine blue, carbonblack, iron oxide or the like to impart color to the coating or withsilica, clay, talc and the like to impart the desired film and solutionproperties to the polysalt and subsequently formed polymer. The polysaltwhich is deposited on a substrate may be used as a coating in itself,due to the hard, cohesive properties of the polysalt after the solventand/or water and ammonia evaporate, or the polysalt can be heated toform the polymer of formula III or the cross-linked version thereof. Iffire retardant coating properties are desired, the polysalt film itselfis the desired coating, however, the polymer of formula III or thecross-linked version thereof also imparts fire retardantcharacteristics.

In addition, adhesive compositions can be formed by the polymers of theinstant invention in that the polymer structure can be adapted to havebonding characteristics to metal, glass, mica, asbestos, wood, paper andlike substrates.

The invention will be more clearly illustrated by the examples below;however, these examples which describe specific embodiments should notbe construed to limit the invention in any way.

EXAMPLE I Solution A

To a 2 liter round bottom flask equipped with a water cooled refluxcondenser, a thermometer, a heating mantle and a mechanical agitator wascharged 500 grams of trimellitic anhydride (1,2,4 benzenetricarboxylicacid monoanhydride) and 500 grams of ethyl alcohol. The mixture washeated to reflux and refluxed for 1 hour and then cooled to roomtemperature. The mixture did not form a solution. 250 grams of the abovemixture was placed in a five liter beaker and manually agitated atambient temperature with 500 grams of water and 500 grams of ethylalcohol until a clear solution was formed.

Solution B

52 grams of 85% hydrazine hydrate was added to 350 grams of water atambient temperature and manually agitated until homogeneous.

Polysalt formation and binder solution

Solution B was added to Solution A with manual agitation at ambienttemperature and stirred until homogeneous. Subsequently, 1152 grams ofwater was added to the above solution at ambient temperature withagitation and a homogeneous solution resulted.

Application to glass fiber paper

Glass fiber paper was dipped in the binder solution for about 3 secondsand then the glass fiber paper (100% glass fibers) with the bindersolution thereon was heated to 300°F. for 1 hour in a forced air oven.Microscopic examination of the coated glass fiber paper showed a uniformcoating of binder on the glass fibers. Two samples of glass fiber papercoated as above described exhibited good strength and after 4 hours ofsubjecting the above coated glass fiber paper samples to 600°F., thepolymer weight loss of each sample was 16.41% ± 0.61%.

EXAMPLE II

A binder solution was formed in accordance with the components andprocedure of Example I, but the additional 1152 grams of water was notadded after the polysalt was formed.

This binder solution was applied to the glass fiber paper (100% glassfibers) by supporting said paper on a Buchner funnel having the sameinterior dimensions and configuration as the glass fiber paper, andpouring the binder solution onto the glass fiber paper while applying avacuum to the surface of the glass fiber paper opposite the surface ofinitial contact with the binder solution. Two samples of the glass fiberpaper coated as above described exhibited good strength and aftersubjecting the above coated glass fiber paper samples to 600°F. for 4hours, the polymer weight loss of each sample was 11.64% ± 0.20%.

EXAMPLE III Preparation of Terephthaloyl Dihydrazide

To a 2 liter round bottom flask equipped with a water cooled refluxcondenser, a thermometer, a heating mantle and a mechanical agitator wascharged 388 grams of dimethyl terephthalate, 473 milliliters of 85%hydrazine hydrate and 1 liter of ethanol, the above mixture was held atreflux for 12 hours and allowed to cool. After cooling to ambienttemperature, the crystalline terephthaloyl dihydrazide was filtered andwashed with denatured alcohol and subsequently vacuum dried.

Solution A

To a 2 liter round bottom flask equipped with a water cooled refluxcondenser, a thermometer, a heating mantle and a mechanical stirrer wascharged 192 grams of trimellitic anhydride and 350 grams of ethylalcohol. The mixture was heated and refluxed for 1 hour and then cooledto room temperature. The mixture formed a homogeneous solution.

Solution B

213 grams of terephthaloyl dihydrazide was mixed, employing manualagitation, in a three liter beaker with 500 grams of pyrollidone and 200grams of water at ambient temperature until a homogeneous solution wasformed.

Polysalt formation and binder solution

Solution A was added to Solution B manual agitation at ambienttemperature.

The above binder solution was coated on 100% glass fibers in accordancewith the procedure of Example II. Two samples of the glass fibers coatedas above described, exhibited good strength and after subjecting theabove coated glass fiber paper samples to 600°F. for 4 hours, thepolymer weight loss of each sample was about 50%.

EXAMPLE IV Solution A

To a 2 liter round bottom flask equipped with a water cooled refluxcondenser, a thermometer, a heating mantle and a mechanical agitator ischarged 192 grams of trimellitic anhydride and 350 grams of ethylalcohol. This mixture is heated to reflux for 1 hour and allowed to coolto room temperature.

Solution B

40 grams of 85% hydrazine hydrate is mixed using manual agitation, with350 grams of water at ambient temperature in a three liter beaker.

Polysalt formation

Solution A is added to Solution B at ambient temperature using manualagitation. A homogeneous solution was formed.

The above polysalt is coated on a cold rolled steel panel and allowed toair dry for 24 hours. A film produced in this manner is continuous, hardand demonstrated fire retardancy when exposed to open flame.

Although the present invention has been described with respect tospecific details of certain embodiments thereof, it is not intended thatsuch details act as limitations upon the scope of the invention exceptinsofar as is set forth in the accompanying claims.

We claim:
 1. An article of manufacture comprising: a polymer having therepeating structural formula: ##EQU10## deposited on a substrateselected from the group consisting of fibrous metallic and cellulosicsubstrates; and wherein R₁ is a divalent organic radical selected fromthe group consisting of alkylene, arylene and heterocyclic, R₂ and R₃are monovalent alkyl, aryl, aralkyl, cycloalkyl or hydrogen radicals andx and y are either 1 or
 0. 2. The article of claim 1 wherein the fibroussubstrate is glass fibers.